Table 1.

Steady-state kinetic parameters of wild-type and QBS mutant TrSqrF enzymes for DQ and dUQ substrates

Protein	kcat (s−1)		Km (μM)		kcat/Km (μM−1 s−1)
	DQ	dUQ	DQ	dUQ	DQ	dUQ
SqrF WT	1.25 ± 0.04	8.37 ± 0.33	27.39 ± 2.47	24.47 ± 6.42	0.046	0.342
SqrF V331A	0	2.47 ± 0.33**	n.d	18.99 ± 6.10	n.d	0.130
SqrF V331F	0.72 ± 0.02**	3.64 ± 1.06**	40.23 ± 7.36*	12.33 ± 0.86*	0.018	0.295
SqrF I333F	0.72 ± 0.21*	1.20 ± 0.48**	102.7 ± 69.9	13.98 ± 7.20	0.007	0.086
SqrF F366A	0.26 ± 0.01**	1.97 ± 0.28**	46.19 ± 2.53**	9.38 ± 1.97*	0.006	0.210
SqrF F366Y	0.57 ± 0.08**	3.17 ± 0.82**	79.30 ± 14.68**	10.03 ± 1.39*	0.007	0.316
SqrF CTD	0.96 ± 0.24	4.90 ± 0.80**	70.71 ± 44.78	18.99 ± 0.67	0.014	0.268

The Welch’s t test was used to calculate the significance values in R Studio software

^*p-value < 0.05; **p-value < 0.005